摘要:
A member for semiconductor devices comprising a composite alloy of aluminum or an aluminum alloy and silicon carbide, wherein silicon carbide grains are dispersed in aluminum or the aluminum alloy in an amount of from 10 to 70% by weight, the amount of nitrogen in the surface of the member is larger than that in the inside thereof, and the ratio of aluminum or the aluminum alloy to silicon carbide is the same in the surface and the inside. The member is produced by mixing powdery materials of aluminum or an aluminum alloy and silicon carbide, compacting the mixed powder, and sintering the compact in a non-oxidizing atmosphere containing nitrogen gas, at a temperature between 600.degree. C. and the melting point of aluminum. The member is lightweight and has high thermal conductivity as well as thermal expansion coefficient which is well matches with that of ceramics and others. Therefore, the member is especially favorable to high-power devices.
摘要:
A mold assembly has a fixed mold incorporating a base with a movable member supported thereon so as to be movable relative thereto and which is closed against a movable mold by a spring. A protrusion on the base passing through the movable member, and a recess on the movable mold engage to form a cavity. A runner and a gate are formed between the movable member and movable mold. Resin is filled into the cavity with the mold lightly closed and the movable member and movable mold closed, but with the movable member and base apart. During filing, the movable member and base open under resin pressure which is held constant inside the cavity. The movable member and base are then closed and when the gate closes with engagement of the protruding and recess portions, a constant amount of resin remains in the mold cavity, which is then compressed.
摘要:
A material powder is packed in a cavity of a mold with high and uniform density to manufacture a powder molding a material powder in a shoe box 12 is fed into a cavity 6 formed in a mold 1 by moving the shoe box 12 over the cavity 6 while oscillating the shoe box until the density of the powder in the cavity increases to at least 1.1 times the apparent density. The powder is then compression-molded.
摘要:
A low alloy sintered steel contains at least 0.15 percent by weight and less than 0.8 percent by weight of carbon. Its matrix is formed by a tempered martensite containing prior austenite crystal grains of not more than 15 .mu.m in mean grain size. Pores and nonmetallic inclusions contained in the matrix are not more than 50 .mu.m in maximum diameter, and the density of the low alloy sintered steel is at least 96 percent of theoretical density. A raw material powder for forming the low alloy sintered steel includes iron alloy powder which is prepared by an atomizing process, and is treated with a dry mill in an inert gas atmosphere or in the atmospheric air. Thus, dislocations are introduced into the raw material powder, and nonmetallic inclusions contained in the raw material powder are pulverized to be not more than 50 .mu.m in maximum diameter. Not only static characteristics but also dynamic characteristics, such as fatigue strength, of the low alloy sintered steel are improved.
摘要:
A quarter-wave distributed-constant dielectric filter or resonator having a ceramic body which typically is composed principally of barium titanate. The ceramic filter body has one or more resonance holes extending therethrough. A conductive covering of silver or the like on the filter body has a portion formed on the surface defining each resonance hole. Mounted in each resonance hole is a prefabricated capacitor having a first terminal extending from within the resonance hole. The second terminal is electrically coupled to the conductive covering on the surface of the resonance hole. The capacitance of the capacitor or capacitors can be known before they are mounted to the filter body, so that the filter is readily manufacturable to exact electrical characteristics desired.
摘要:
In an injection molding process, male and female dies are first clamped together by a prescribed clamping force to provide surfaces defining a cavity of a prescribed extruded area therebetween. Then, a molten resin is injected at a prescribed injection pressure into the cavity until the cavity is filled with the molten resin. Subsequently, the molten resin filled in the cavity is held at a prescribed holding pressure, so that the resin within the cavity solidifies to produce a molded article. The injection pressure in the injecting step is controlled so as to decrease immediately before the cavity is filled with the molten resin to thereby prevent a pressure boost from occurring upon the termination of the injecting step. The holding pressure in the holding step is controlled in such a manner that a maximum of the pressure of the resin within the cavity in the holding step is higher than a maximum of the pressure of the resin within the cavity in the injecting step.
摘要:
A silicon carbide based composite material includes as a first component, a metal mainly consisting of aluminum or copper, and as a second component, particles mainly consisting of silicon carbide having high purity and few defects. The material is obtained by heating a compact of the raw material powder containing the first and second components at a temperature not lower than the melting point of the metal mainly consisting of aluminum or copper, and by forging and solidifying under pressure. Preferably, the silicon carbide raw material powder is prepared to have high purity by carrying out a preliminary treatment, or the material after forging or a material obtained through a conventional infiltration process is further heated at a temperature lower than the melting point of the first component. In this manner, an improved superior thermal conductivity can be obtained.
摘要:
Disclosed herein is a photoreceptor for electrophotography having an over coating layer formed on a substrate and prepared by applying a composition containing silica particles, an organic compound chemically bonded thereto and a photo polymerization initiator and by curing said composition; said organic compound having an polymerizable unsaturated group, a group designated by Formula (1) or a group designated by Formula (2), and said silica particles and said organic compound being bonded with each other through a silyloxy group. The photoreceptor for electrophotography has not only excellent durabilities and an excellent resistance to printing but also excellent electrophoto characteristics such as sensitivity and a residual potential. ##STR1## (wherein --X-- is selected from --NH--, --O-- and --S--, --Y-- is an oxygen atom or a sulfur atom, and when --X-- is --O--, Y is said sulfur atom).
摘要:
In a powder forging process, a heated green compact is placed in a stationary die and subjected to a press-forging carried out mainly to reduce the thickness thereof by cooperation of the stationary die with a movable die. The press-forging is performed at two pressing steps. After placement of the green compact into the concave molding portion of the stationary die, the pressing step were carried out. Thus, it is possible to produce a forged product having a high strength and a high toughness. A heated heat insulator also may be placed in the stationary die to provide a temperature-retaining effect to the green compact before and during pressing.
摘要:
A method of producing rocket combustors wherein in forming an outer cylin by a powder metallurgical method on the outer side of a cylinder provided on its outer periphery with a cooling wall of channel construction having a plurality of grooves, a low-melting alloy is used as a filler to be filled into the grooves. It is also possible to form the outer cylinder after forming a Cu plating shell on the periphery of the inner cylinder filled with the low-melting alloy.